This invention relates in general to adjustable layout squares, namely instruments which can be used in diverse applications for measuring and setting out markings on a workpiece at predetermined angles and/or distances. For example, adjustable layout squares can be used in drafting or generally in setting out patterns on wooden workpieces in carpentry work or on steel plate in sheetmetal work and the like.
Squares of many different designs are known in the art. Commonly known forms of squares, for example, include right angle or framing squares, comprising orthogonally disposed limbs or blades each marked with a scale, set squares of triangular form usually having a pair of orthogonal sides and a hypotenuse at a specified angle, such as 45.degree. or 60.degree. , and adjustable set squares in which the angle of the hypotenuse can be varied. Adjustable squares or bevels comprising an orthogonal framing square with an extra blade which can be slid along the respective limbs to vary its angle are also known. Thus, certain such known instruments are disclosed, for example in the following U.S. patents:
______________________________________ 820,311 May 8, 1906 824,821 July 3, 1906 866,111 Sept. 17, 1907 973,584 Oct. 25, 1910 1,039,057 Sept. 17, 1912 1,674,882 June 26, 1928 4,028,814 June 14, 1977 ______________________________________